Does flash make for a sharper picture?

[rgiddings]

My eyes tell me that flash beats fast shutter speed for getting maximum sharpness out of a lens. I'm not sure why, though. If it were just the shortness of the exposure reducing camera shake, wouldn't we see sharpness increase when shooting, say, 1/4000 in continuous light? Maybe flash produces higher local contrast or something. Ideas?

 

[Sailor Blue]

The duration of a hot-shoe flash is very short, generally less than 1/500 sec at full power and progressively shorter as the power is reduced.

You have to remember that unless you are using a flash capable of High Speed Sync that your flash shutter speed is limited to the camera sync speed, generally to 1/200 sec t 1/250sec. With focal lengths longer than even 100mm it is easy to get camera shake at these shutter speeds.

Using flash as the main light with low ambient light levels can indeed make images sharper by eliminating camera shake. Typical would be shooting with flash indoors or outdoors at night.

If the ambient light is high such as outside during the daytime, where the flash is only used as a fill light, then you can still see camera shake.

Light from a hot-shoe flash is also coming from a very small light source so it is very hard light. Hard light from the side, such as from an off-camera hot-shoe flash, accentuates edges by casting sharp shadows that your camera can see. These hard edged shadows give the impression of greater sharpness.

Hard lighting from the side is a great way to illuminate a rugged weathered face of a man but you won't find may women who appreciate being lit this way since it makes the skin texture, wrinkles, and any blemishes show up clearly.

 

[historianx]

Yes it does, and much clearer. For example, I shoot a lot of runway fashion, and use flash all the time because designers and makeup artists like to see their creations in as punchy, accurate and clear renditions as possible, without all the muddiness and whacked out white balance issues that those relying on available light produce. The dress is red, not orange...

IOW, if I cant see the color of the model's eyes, esp on a tight point shot, then the rest of it's not going to meet mine, or the designer's standards. I also think that many photogs have an irrational fear of using flash for this work, based around the possibility they may not know what they are doing.

 

[Freeman-Jo]

historianx wrote:

IOW, if I cant see the color of the model's eyes, esp on a tight point shot, then the rest of it's not going to meet mine, or the designer's standards. I also think that many photogs have an irrational fear of using flash for this work, based around the possibility they may not know what they are doing.

In the older day, flashes are not TTL. They were manual, and for most people they are harder to control for most usage. Studio shot are different since we shoot manual anyway. In today age, most flashes have some sort of TTL metering and most flash will fire as a fill-in flash rather than to a full blast. As long as the photographer will just bounce the flash off something to have the light indirectly wrap around the subject rather than direct frontal hit on the subject, it's harder to screw up now.

 

[24Peter]

rgiddings wrote:

My eyes tell me that flash beats fast shutter speed for getting maximum sharpness out of a lens. I'm not sure why, though. If it were just the shortness of the exposure reducing camera shake, wouldn't we see sharpness increase when shooting, say, 1/4000 in continuous light? Maybe flash produces higher local contrast or something. Ideas?

I wouldn't rely on your eyes in this case. In some situations, the (relatively) short duration of a flash may make an image appear sharper, but optics, sensor resolution, shutter speed and camera/subject movement are truly determinative of image sharpness.

All things being equal, at shot taken at 1/8000 will probably appear sharper than one taken at 1/80th, unless you're shooting with a steady platform like a tripod. Then you probably can't tell the difference.

Re; local contrast - Does a shot taken outdoors under bright sunlight have less sharpness than one taken with your flash?

Again, eyes are not the way to measure this.